Input sources should NOT effect the brite. Look for picture mode
settings. Like normal-sports-theater-demo, etc Demo mode is
really nasty. Its used in the stores to really give the set a look
that stands out but at home looks like crap. Too much color etc.
Also look for any settings for a light sensor. Bottom line is
run all controls set to normal.
Other thing to consider is watching it in a dark room. That way
the brite can be turned down. The set will run cooler & probably
last longer. I run my Sony about half brite & its 11 yrs old now &
still runs perfect.
73 Zeno
LFOD !